Methods and apparatus for dispensing paramagnetic articles



March 28, 1967 F. J. BROWN METHODS AND APPARATUS FOR DISPENSING PARAMAGNETIC ARTICLES Filed March 10, 1966 R V mm M mm H vs m mu m F 0 V, B 2 G M n K 1 a 8 a a 2 a m 2 N m Pym J0... N a ibi! wmw M A H j if an m 2 a? 1 5 2m 2 a j V 2 0 mwH z T -w m W M 4\ W5 2 United States Patent C) 3,311,259 METHODS AND APPARATUS FOR DEPENSENG PARAMAGNETIC ARTICLES Ford J. Brown, Kutztown, Pa., assignor to Western Electric Company, Incorporated, New York, N.ir., a corporation of New York Filed Mar. 10, 1966, Ser. No. 533,172 8 Claims. (til. 221-1) This invention relates generally to methods and apparatus for dispensing paramagnetic articles, and more particularly to the dispensing of small, fragile paramagnetic parts individually in an oriented manner. Accordingly, the general objects of the invention are to provide new and improved methods and apparatus of such character.

In the manufacture of various products involving small, usually fragile, paramagnetic parts, it is desirable to load a large number of the parts into receivin apertures in a tray or rack to permit mass treatment or processing of the parts. Accordingly, another object of the invention is to provide new and improved methods and apparatus for feeding and then dispensing a succession of such parts at selected times so as to load them individually into apertures in a receiving tray.

One specific application of the invention is in the handling of contact reeds used in the manufacture of scaled contacts for ferreed switches, each of which includes two reeds sealed in parallel, overlapping relationship in a glass envelope. The reeds are composed of a paramagnetic material, having their tips plated with a conductive metal such as silver and/or gold to provide good conductivity between the reeds. Inasmuch as the reeds are very small and fragile, conventional clampingtype racks are not suitable for holding the reeds during the electroplating operation because of the possibility of damage to the reeds and because it is very difficult to load the reeds in such racks. In order to facilitate plating of the reeds on a mass production basis, it is desirable to arrange a large group of the reeds in apertures of an electroplating tray with the tips to be plated protruding from the tray.

Accordingly, another object of the invention is to provide simple and inexpensive methods and apparatus for rapidly loading groups of such reeds in the desired orientation into receiving apertures of a tray preparatory to a mass processing operation, such as electroplating.

With the foregoing and other objects in View, a method illustrating certain features of the invention includes the step of advancing paramagnetic articles in a singlefile line along a nonmagnetic trackway. The leading article is magnetically attracted and held against the trackway until it is desired to dispense an article, at which time the next following article is held magnetically and the leading article is released. Magnetic poles of the same polarity are induced at both the trailing end of the leading article and the leading end of the following article, whereupon the following article repels the leading article to permit it to be dispensed from the trackway. Apparatus in accordance with the invention may include a trackway 'and magnetic means for holding the leading and following articles as described, and for inducin like poles at the adjacent ends of the front two articles.

Preferably, a supply of the articles are fed into the upper end of a gravity chute for advancement in a singlefile column toward the lower end of the chute. A magnet assembly is initially positioned near the lower end of the chute to stop the leading article. The magnet assembly has end portions of the same polarity, which align with the ends of the leading article so as to induce poles of the opposite polarity at both ends of that article. To dispense an article, the magnet assembly is moved upward along 3,3 1 1,25 9 Patented Mar. 28, 1957 the chute to a dispensing position where it aligns with the following article, so that the leading article is repelled by the following article and is dispensed from the chute by gravity.

Other objects, advantages and features of the invention will be apparent from the following detailed description of a specific embodiment therof, when read in conjunction with the appended drawings, in which:

FIG. 1 is a partially schematic view of a dispensing apparatus in accordance with the invention, illustrating the manner in which sealed contact reeds are fed into 'a gravity chute for dispensing;

FIG. 2 is a perspective view of a sealed contact, showing the arrangement of the contact reeds; and

FIG. 3 is a view similar to a portion of FIG. 1, illustrating the manner in which the contacts are dispensed from the chute into a receiving rack.

Referring now in detail to the drawings, 'and particualarly to FIG. 1, the specific embodiment of the invention relates to a magnetic escapement mechanism 18- for dispensing a succession of paramagnetic contact reeds 11-11 used in the manufacture of sealed contacts. As illustrated in FIG. 2, each sealed contact 12 includes a pair of the reeds 11-11 sealed in parallel, overlapping relationship in a glass envelope 13. Each reed 11 has a cyclindrical middle section 14 and a pair of flat, paddlesh'aped end sections 16 and 17, one of which (the section designated 16) is longer than the other.

As viewed in FIG. 1, the escapement mechanism 10 is designed to dispense a succession of the reeds 11-11, one at a time, into a row of receiving apertures 18-18 in an electroplating rack 19, so that the short end 17 of each reed is down and the tip 21 of the long end 16 projects above the surface of the rack 19. With this arr'angement, the tips 21-21 of a large number of reeds may be electroplated simultaneously with conductive metals such as silver and gold, prior to assembly of the contact 12 with the tips 21-21 overlapping as shown in FIG. 2.

In order to dispense a succession of the reeds 11-11 individually at a desired rate, a supply of the reeds 11-11 are advanced in a single-file line along a nonmagnetic trackway 22 toward the escapement mechanism 1%. In the specific embodiment, the traclrway 22 comprises a gravity chute 23 arranged vertically a short distance above the rack 19, so that each reed 11 in the line may drop by gravity, when released by the escapement mecha nism 11?, and fall into one of the apertures 13-18 in the rack. The rack 19 is intermittently advanced by an indexing mechanism 24, and the rate of dispensing is correlated with the advancement of the rack such that one reed 11 is dropped into each successive aperture 18.

Preferably, the reeds are fed automatically into the upper end of the chute 23 by a feeding and orienting device 25, which is capable of feeding the reeds at a rate faster than they are to be dispensed. In this manner, a column or stack of the reeds is always maintained in position above the rack 19, waiting to be dispensed. Various known vibratory feeding and orienting devices may be used to feed the reeds into the chute 23 at the desired rate, and to orient the reeds such that the short end 17 of each reed is down. The cross-sectional area of the passage in the chute 23 should provide sufficient clearance for the reeds to fall through the chute when they are free to move, but otherwise to constrain the reeds to stack end-to-end in a column, as illustrated.

In a specific embodiment, the magnetic escapement mechanism comprises a pair of permanent magnets 26 and 27 positioned adjacent to the chute 23 and having a combined span X somewhat less than the length of one reed 11. As illustrated, the magnets 26 and 27 are separated from each other by a non-magnetic spacer bar 28 to which the magnets are secured, and the entire assembly may be reciprocated up and and down along the chute 23 by a reciprocating mechanism 29, such as an air cylinder or solenoid. FIG. 1 shows the initial, or rest position of the apparatus, wherein the magnets 25 and 27 are positioned near the lower end of the chute 23 and are approximately aligned with the ends of the leading reed, designated 11A. The magnets must be sufiiciently strong to attract and hold the leading reed 11A against the wall of the chute 23, to stop the advancement of that reed and all following reeds in the chute. As previously mentioned, the reeds 1111 are composed of a paramagnetic material, by which is meant a material capable of experiencing attraction by a magnet and of holding a flux density field for a sufiicient time to create 'a repulsive or attractive force on adjacent reeds for the purposes of the invention. In the particular example, the material is 52 alloy, an alloy consisting of approximately 52% nickel and 48% iron.

In order to dispense the leading reed 11A, the escapement mechanism 10 is moved upward along the chute 23 from the initial position illustrated in FIG. 1 to a dispensing position illustrated in FIG. 3, in which the magnets 26 and 27 hold the next following article 118. In this position, the lower end of the magnet 26 is positioned a short distance above the leading end of the following reed 118, as shown. The strength of the magnets 26 and 27 must be insufiicient to lift the leading reed 11A an appreciable distance against gravity and the weight of the following reeds, so that this second aligning and holding step may be performed while leaving the leading reed 11A approximately in its initial position.

A significant feature of the invention resides in the arrangement of the magnetic escapement mechanism 10, such that magnetic poles 3131 of the same polarity are induced at both the trailing end of the leading reed 11A and the leading end of the following reed 11B. With this arrangement, the following reed 11B repels the leading reed 11A when the escapement mechanism moves to the dispensing position, as illustrated in FIG. 3, so as to disengage the reed 11A from the reed 11B and permit the reed 11A to fall by gravity through the remaining length of the chute 23 and fall into the aligned slot 13 in the tray 19. Were it not for this method of inducing identical poles at the adjacent ends of the front two reeds, it would be difficult or impossible to extricate the leading reed from the following one so as to insure rapid dispensing of the leading reed.

While there 'are various possible arrangements of permanent magnets and/ or electromagnets which can be used to induce this adjacent-polarity repelling action, a simple and effective arrangement is employed in the illustrative embodiment of the invention, involving a pair of spaced permanent magnets 26 and 27, arranged as shown with like poles facing each other. For example, if the north poles face each other as shown, the south poles will be located at the extremities of the span X, and will thus he opposite to the ends of the leading reed 11A in the FIG. 1 position and opposite to the ends of the following reed 11B in the FIG. 3 position. In this manner, north poles are induced at both ends of the reeds 11A and 11B in the two successive stages of operation.

After the leading reed 11A has been dispensed, the escapement mechanism 10 is returned to the initial position (FIG. 1) in preparation for another dispensing operation. As this occurs, the reed 11B moves down the chute 23 with the magnets 26 and 27 and comes to the rest position formerly occupied by the reed 11A. The remaining reeds 11 -11 in the chute are thus free to advance by gravity one step, and a space is created at the top of the column which is filled by the feeding and orienting device 25. In this manner, a continuous supply of the reeds is always available in the chute 23 so long as the feeding and orienting device 25 is capable of feeding at same or a faster rate than the reeds are dispensed.

After the escapement mechanism 10 has returned to the initial position, the rack 19 is indexed one step forward (to the left as viewed in FIG. 1) to align the next slot 13 with the lower end of the chute 23. Various arrangements of switches and timing mechanisms may be employed to reciprocate the escapement mechanism 10 in timed relationship with the indexing of the rack 19 so as to load the racks automatically. In one example (not shown), a cam is rotated in response to the indexing movement of the rack 19 so as to actuate a solenoid each time the rack indexes one step. The solenoid elevates the escapement mechanism It) to the dispensing position, and a limit switch senses the arrival of the mechanism 10 at the dispensing position and, after a short time delay, reverses the solenoid to return the mechanism 10 to the initial position.

VJhile only a single column of contacts is shown in the drawings, in practice it is desirable to dispense a relatively large number of the reeds 1i11 at the same time. In one example, fifty columns of reeds are fed simultaneously through parallel chutes or trackways arranged in two rows of twenty-ive. The magnets in this instance comprise relatively long bar magnets which operate on a plurality of tracks simultaneously.

While one specific embodiment of the invention has been described in detail, it will be obvious that various modifications may be made from the specific details described without departing from the spirit of the invention. In parti ular, various arrangements of trackways and magnets may be employed so long as the essential steps of the invention are followed; advancing the articles in a singlefile line along a trackway and dispensing them magnetically in two stages such that like poles are induced at the trailing end of the leading article and at the leading end of the trailing article, to repel the leading article and thereby permit it to be dispensed from the trackway.

What is claimed is:

1. The method of dispensing paramagnetic articles, which comprises:

advancing the articles in a single-file line along a nonmagnetic traclrway;

magnetically attracting and holding the leading article against the trackway to stop the advancement of arti-' cles therealong, while inducing a magnetic pole of one polarity at the trailing end of the leading article;

magnetically attracting and holding the next following article against the trackway, while inducing a magnetic pole of the same polarity at the leading end thereof; and

releasing the leading article, whereupon the following article repels the leading article to permit it to be dispensed from the trackway.

2. The method as recited in claim 1, wherein:

the advancing step is performed by feeding a supply of the articles into an upper end of a gravity chute, comprising the trackway; and

the attracting and holding steps and the releasing step are performed by moving a single magnet assembly up and down along the chute whenever it is desired to dispense one of the articles, the magnet assembly having end portions of the same polarity so as to induce magnetic poles of the opposite polarity at both ends of both the leading article and the following article.

3. Apparatus for dispensing paramagnetic articles, which comprises:

a nonmagnetic trackway along which the articles are advanced in a single-file line;

magnetic means for attracting and holding selected ones of the articles against the trackway to stop the advancement of articles therealong; and

means for operating the magnetic means in two stages, first to hold only the leading article and second to hold only the next following article, the magnetic means including magnetic poles so arranged as to induce a magnetic pole of one polarity at the trailing end of the leading article and a like pole at the leading end of the following article, whereby the following article repels the leading article to permit it to be dispensed from the trackway.

4. Apparatus as recited in claim 3, wherein the magnetic means comprises at least one magnet assembly having a span approximately equal to the length of one article and having end portions of the same polarity which align with the ends of each article being held so as to induce magnetic poles of the opposite polarity at both ends of both the leading article and the following article.

5. Apparatus as recited in claim 3, wherein:

the magnetic means comprises a single magnet assembly; and

means are provided for reciprocating the magnet assembly back and forth along the track between a position where it aligns with the leading article and a position where it aligns with the next following article.

6. Apparatus as recited in claim 3, wherein the trackway comprises a gravity chute having an upper end into which the articles are fed and a lower end from which the articles are dispensed by gravity after the following article repels the leading article.

7. Apparatus for dispensing paramagnetic articles, which comprises:

a gravity chute of nonmagnetic material having an upper end into which the articles are fed for advancement in a single-file column toward the lower end;

a magnet assembly having a span approximately equal to the length of one article, the magnet assembly being initially positioned near the lower end of the chute and having sufficient strength to attract and hold the leading article against a Wall of the chute to stop the advancement of the leading article and all following articles;

means for moving the magnet assembly upward along the chute from the initial position to a second position where it aligns with the next following article, the strength of the magnet assembly being insufiicient to lift the leading article against gravity and the weight of the following an'cles, the magnet assembly having end portions of the same polarity so as to induce magnetic poles of the opposite polarity at both ends of both the leading article and the following article, whereby the following article repels the leading article and the leading article is dispensed from the chute by gravity; and

means for returning the magnet assembly to the initial position to permit limited advancement of the column of articles through the chute until the following article has moved to the initial position.

3. Apparatus as recited in claim 7, wherein the magnetic assembly comprises a pair of bar magnets, both mounted adjacent to the chute and spaced from each other along the chute, the magnets being arranged with like poles facing each other.

References Cited by the Examiner UNITED STATES PATENTS 2,795,340 6/1957 Hommel 221175 X 3,200,931 8/1965 Voorhies 221212 X 3,253,735 5/1966 Brown et a1 221298 X FOREIGN PATENTS 576,559 4/ 1946 Great Britain.

References @ited by the Applicant UNITED STATES PATENTS 2,471,002 5/1949 Mohr. 2,616,696 11/1952 Field. 2,823,781 2/ 1958 Bosch. 3,184,655 5/1965 Brown.

SAMUEL F. COLEMAN, Primary Examiner. 

1. THE METHOD OF DISPENSING PARAMAGNETIC ARTICLES, WHICH COMPRISES: ADVANCING THE ARTICLES IN A SINGLE-FILE LINE ALONG A NONMAGNETIC TRACKWAY; MAGNETICALLY ATTRACTING AND HOLDING THE LEADING ARTICLE AGAINST THE TRACKWAY TO STOP THE ADVANCEMENT OF ARTICLES THEREALONG, WHILE INDUCING A MAGNETIC POLE OF ONE POLARITY AT THE TRAILING END OF THE LEADING ARTICLE; MAGNETICALLY ATTRACTING AND HOLDING THE NEXT FOLLOWING ARTICLE AGAINST THE TRACKWAY, WHILE INDUCING A MAGNETIC POLE OF THE SAME POLARITY AT THE LEADING END THEREOF; AND RELEASING THE LEADING ARTICLE, WHEREUPON THE FOLLOWING ARTICLE REPELS THE LEADING ARTICLE TO PERMIT IT TO BE DISPENSED FROM THE TRACKWAY. 